‘Could you make sure the picture stays where it is until I come back? I don’t care about buying it—I don’t want it. But I need to show it to my boyfriend and . . . I don’t know where he is.’

‘The tall bloke in the donkey jacket you were looking for?’

I nodded.

She sighed, and seemed to soften. ‘I’ll do my best,’ she said, ‘but if the buyer comes to pick it up, there’s not an awful lot I can do.’

I left without saying thank you or goodbye. I’d wasted enough time already. She was right. Assuming Abberton really was sold and she wasn’t lying, the person who had bought it could arrive to collect it at any moment. I ran outside and stuck out my arm to stop a taxi, then realised there weren’t any, only several people who looked as if they were waiting. One glanced at his watch, sighed and walked off down the road.

‘Come on,’ I breathed through gritted teeth. A taxi had to come. I had to get back to the hotel—that’s where Aidan would be. He’d have gone back there to check out, to pick up our bag and the Gloria Stetbay. A taxi appeared, and a woman in a grey trouser suit with a mobile phone pressed to her ear moved forward to greet it. She opened the back door. I ran at her with my wallet already open and offered her twenty pounds if she’d let me take it instead. It was an emergency, I told her. She looked unconvinced, but took the money and stepped back, relinquishing the cab.

At the Drummond, I told the driver to wait outside for me. I didn’t have the patience to wait for the lift, so I ran up four flights of stairs to room 436. I banged on the door and called Aidan’s name. ‘Please be here,’ I whispered. ‘Please.’

The door opened, but not very far. I heard footsteps walking away. I pushed the door fully open, banging it against the wall. Aidan stood in the centre of the room with his back to me. Short of leaving me stranded outside in the corridor, he couldn’t have been less welcoming. I didn’t care; I knew this bad patch would end as soon as he’d heard what I had to say. ‘Mary Trelease, ’ I panted.

He swung round.

‘What does she look like?’

‘I don’t know. That depends how long it takes a body to decay. You’d need to ask a pathologist.’

‘Skinny, masses of black curly hair that’s starting to go grey, cut-glass accent, bad skin—lined, like a much older woman’s. Pale brown mole beneath her lower lip that’s shaped like . . . like a double-ended spanner, sort of. Or how you’d draw a dog’s bone in a cartoon . . .’